Apparatus for folding sheets of fabric and the like



J1me 1940- J. H. BRACKETT APPARATUS FOR FOLDING SHEETS OF FABRIC AND THE LlKL 6 Shes-ts-Sheet 1 Filed 001;. 2 3-, 1938 23 334 33.36 209 35 'JA ME 6 Y 1 HA RR/J) K; c H) F0 5715/? a I'm RR AS A T TO KN: 45

J. H. BRACKETT June 1 1, 1940.

APPARATUS FOR romme smsms OF FABRIC AND THE LIKE Filed 001:. 24, 1938 6 Sheets-Sheet 5 .2 J 6 6 4 3 Ed m 7 6 4 w fdo //v VEN TOQ \JA M55 H. BRA one 77' Hum BY HARR/J, K/ECH, FOJTER 6' HARRIS June 11, 1940- J H. BRACKETT APPARATUS FOR FOLDING SHEETS OF FABRIC AND THE LIKE Filed Oct. 24, 1938 6 Sheets-Sheet 4 llrlllllI/Illllllll/II:IIIlIlI/I l/VVENTOR J H. BRACKETT JAME 6) HA RR/J) K/ECH) F0; 75/? a HA RR/J 27 ceF )"OPT June 11, 194-0. J. H. BRACKETT 2,204,263

APPARATUS FOR rowme SHEETS 0F FABRIC mm was LIKE 6 Sheets-Sheet 5 338 HARR/J, K/EcH, FOJTER & HARRIS STACK/NG MECHA/V/JM \SECONDAQY FOLDING MECHANIJM PRIMARY FOLD/N6 MECHAlV/J'M June 11, 1940. J H. BRACKETT 2,204,268

APPARATUS FOR FOLDING SHEETS 0F FABRIC AND THE LIKE Filed Oct. 24, 1938 6 Sheets-Sheet 6 OPERATION JE UE/VCE FOR ONE MACH/NE CYCLE DEGREES ROTA T/ON OF MAIN Jl-IAFT I22 v T 5 //vv/v7'o& /A MEJ H. BRACKETT 65 70 By HA RR/J, K/ECH) F05 7'51? & HARR/J Patented June 11, 1940 UNITED STATES APPARATUS FOR FOLDING SHEETS OF FABRIC AND THE LIKE James H. Brackctt, Pasadena, Calif.

Application October 24, 1938, Serial No. 236,716

9 Claims.

My invention relates to folding devices, particularly devices for folding sheets of flexible material, and is directed specifically to an improved method and apparatus for folding such sheets automatically in rapid succession. While my invention has wide application in various fields, it offers outstanding advantages when embodied in a laundry machine designed to fold flat-Work. For the purpose of this disclosure, I elect, therefore, to describe such a machine, but it is to be understood that my invention is not limited to any specific field.

One object of my invention is to provide a compact folding machine that is flexible in the sense that it may be employed equally well for a long run of uniform flat-work for hotel, hospital and linen supply service and for runs of family flat-work of non-uniform sizes. More specifically, I propose to design a folding machine that will not require adjustment for handling different sizes of flat-work.

Various folding machines heretofore proposed and employed have been cumbersome, bulky de vices that are wasteful of space especially when out of service. Another object of my invention is to provide an efiicient, compact machine having the character of a table and serviceable as a table when not employed as a folder.

In the prevailing practice, fiat-work is transported from a mangle to a table for folding by hand. It has been found that approximately sixty per cent of the time consumed in the manual procedure of folding is devoted topicking up the sheet of material and spreading it out on the Work-table, only forty per cent of the time being required to carry out the subsequent folding operations. One object of my invention is to provide a portable or semi-portable folding machine adapted to receive work directly from a mangle. When employed in this manner, my invention eliminates entirely the usual transportation to a folding table, and since the sheet of material is discharged from the mangle in a flat disposition the usual operation of spreading out the sheet of material preparatory to folding is also eliminated. It is contemplated that the only manual operation required between the mangle and the folding machine will be guidance to a feed position on the folder.

A further object of my invention is to incorporate in such a folding machine, means for receiving the finished articles that is adapted to build up a stack of the finished articles for transportation away from the folder. More specifically, it is my purpose to receive the finished objects successively on the top of a stack and to maintain the top of a stack at a substantially constant receiving level.

My invention as embodied in the specific form of the present disclosure is characterized by the ,5' conception that a sheet of flexible material such as a towel or a napkin may be folded by forcing the sheet laterally through a slot along a fold line of the sheet. One object of my invention is to provide means acting in sequence to force a flexible sheet through a succession of such slots I to form multiple folds in the sheet.

In the preferred form of my invention I propose to have the unfolded sheet placed initially on an upper support having the character of a table top and to carry the sheet downwardly through successive slots to successively lower levels. A feature of my invention is the conception of a reciprocating tray cooperative with the means that forces the sheets through the final slot, the reciprocating tray facilitating the delivery of the finished article to a finished stack.

Other objects and advantages, particularly those relating to the actuating and timing means incorporated in the folding machine, will be apparent in my more detailed description to follow, 2 taken with the accompanying drawings.

In the drawings:

Fig. 1 is a plan view of the preferred form of my apparatus with the movable parts in the posi-. tions at the beginning of a machine cycle;

Fig. 2 is a front elevation of Fig. 1;

Fig. 2a is an enlarged detail taken from Fig. 2;

Fig. 3 is a side elevation as viewed from the left of Fig. 1; i

Fig. 4 is an enlarged fragmentary view taken as indicated by the line 4-4 of Fig. 1 showing in side elevation the clutch mechanism of the machine;

Fig. 5 is a fragmentary section taken as indicated by the line 5--5 of Fig. 1;

Fig. 6 is a fragmentary vertical section on a slightly enlarged scale taken as indicated by the line 6-6 of Fig. 3;

Fig. 6a is a fragmentary viewyof a track in- I corporated in the apparatus;

Fig, 7 is an enlarged fragmentary section showing the construction of the secondary folding mechanism of the apparatus;

Fig. 8 is a fragmentary view showing a portion of Fig. '7 in plan;

Fig. 9 is a fragmentary vertical section taken as indicated hy the line El -9 of Fig. 7;

Fig. 10 is a side elevation on an enlarged scale of an extensile link employed in my apparatus;

Fig. 11 is a front elevation of Fig. 1i);

Fig. 12 is an enlarged fragmentary view, partly in section, showing mechanism employed to control a tray that is incorporated in the apparatus;

Fig. 13 is a fragmentary section taken as indicated by the line l3-l3 of Fig. 12;

Fig. 14 is a fragmentary View showing in side elevation a cam and cooperative means for controlling a portion of the mechanism employed in my apparatus;

Fig. 15 is a diagrammatic phantom View showing a sheet at various stages in my preferred folding procedure;

Fig. 16 is a digrammatic view showing the movements of a tray and associated mechanism in delivering a finished folded towel to a stack;

Fig. 17 is a graph to indicate the movements of various elements in my apparatus, the move ments being indicated relative to degrees of rotation of a main shaft;

Fig. 18 is a diagrammatic view in perspective of interlocking sprockets associated with the stacking platform of my apparatus; and

Fig. 19 is a diagrammatic view in perspective to indicate the mode of operation of a second embodiment of my apparatus for carrying out a second form of my folding process.

An understanding of my machine in the preferred form may be approached by considering Fig. 15, a phantom view representing the progress of a towel T through the folding process. Initially the towel is spread out on an upper supporting surface, as indicated by the rectangle 20. The first fold in the towel is accomplished by forcing the towel laterally downward along the desired fold line through a suitable slot (not shown), thereby forming a leading folded edge 2|. The movement of the towel is continued to the right until the towel completely clears the slot and comes to rest on a lower supporting surface, the disposition of the folded towel at this stage in the operation being indicated at 22. The second fold is accomplished in the same manner, the towel being again forced laterally downward along a desired fold line through a second suitable slot to form a leading folded edge 23. The towel is moved laterally on a new low :level until the towel completely clears the second slot, the towel then having the final folded disposition indicated at 24.

It will be apparent to those skilled in the art that the path of towel movement in the course of the folding process may be varied widely from that represented by Fig. 15. The path of move ment suggested by Fig. 15, however, has several advantages, including the fact that the suggested sequence of movement lends itself readily to'a machine having the general character of a table in which the folding process is performed in horizontal zones just under the table top.

The mechanism shown in the drawings is supported by a frame generally designated by numeral 25, the frame including a leftward pair of legs 21, a central pair of legs 28, and a rightward pair of legs 29, the legs being interconnected by various frame members, some of which will be identified later.

The primary supporting means upon which the towel or other flexible sheet is initially spread comprises a receiving platform or table generally designated30 that has separate sections 3| and 32 spaced to define a primary slot 35, as best shownin Fig. 3.

The slot-forming edges of these two table sections are rounded to facilitate the movement of a towel through the slot, the forward section 32 being increased in thickness at the slot by a strip 36 to permit a relatively large radius of curvature at the slot. The towel or other flat article to be folded is initially placed on the primary support or receiving platform 30 with the desired first line of fold of the towel coinciding with the primary slot 35.

In accordance with my basic conception I provide means movable against the towel along this line of fold to force the towel laterally downwardly through the slot 35 until the towel completely clears the slot. While a single towel-engaging means may be employed to perform this step, I find it convenient for various reasons to employ one means to force the towel through the slot sufficiently to form a folded edge and then to utilize a second means to engage this folded edge and pull the towel to complete the movement through the slot.

In the preferred form of my invention shown in the drawings, the primary folder for initiating the movement of the towel through the slot 35 comprises a blade 38 mounted on a rectangular frame 39 carried by a rockershaft 40, the rocker shaft being journaled in suitable bearings 4| on the rear of the frame 25. Oscillation of the rocker shaft 40 causes the blade 38 to reciprocate into and out of the primary slot 35, the range of reciprocation of the blade being such that downward movement of the blade will form in a towel the downwardly extending folded edge shown at 2| in Fig. 15. While I prefer to limit the downward movement of the primary folder, as described, it is within the purview of my invention to continue such movement until the towel is completely through the slot whereby the first fold in the towel is completed in one motion. One reason for interrupting the movement of the towel below the slot is that since I propose to confine the folding operation to a horizontal zone of relatively small vertical dimension, it is necessary to change the direction of the towel movement laterally below the slot 35. The mechanical problem involved is simplified if one means is employed to force the towel downwardly through the slot an initial distance and a second means movable laterally is utilized to complete the passage of the towel through the slot.

After the initial movement of the towel through the primary slot 35 accomplished by the primary folder 33, the downwardly extending folded edge 2! of the towel is engaged by a primary puller generally designated 44 that draws the towel laterally in a folding zone lying between the primary support or receiving platform 30 and a lower secondary support 45. To facilitate engagement of the towel by the primary puller 44, I prefer to incorporate in my apparatus a primary lift plate 46 to perform the function of feeding the folded edge portion 2| of the towel to the primary puller 44. The primary lift plate 45 is carried by a rocker shaft 4'! under the rear edge of the slot 35, the plate being actuated to move downwardly as the primary folder blade 35 passes into the slot and to move upwardly as the folding blade withdraws from the slot, the upward movement of the lift plate flexing the folded towel into the operative level of the primary puller 44. The lower swinging edge of the lift plate 16 is recessed or cut away at various points to clear certain towel-gripping means incorporated in the primary puller 44, these recesses being similar to recesses 15 that will be mentioned primary lift plate 45.

noted in the later description of a secondary lift plate (Figs. '7 and 8).

The primary puller may comprise a plurality of grippers generally designated 56 mounted on an elongated carriage 54 that reciprocates between a rearward position near the slot 35 and a second position toward the front of the machine. The construction of the primary puller 44 will be broadly described at this point, but a more detailed understanding may be had by referring to the subsequent description of a secondary puller (see Figs. 7 to 9). i

The carriage of the primary puller is hollow and is movably supported at each end by a roller 52 (Figs 2 and 6), each of the rollers being adapted to traverse a slightly inclined channelshaped track 53. For actuation the carriage 5| may be connected to rack bars 54 at each end thereof and the rack bars engaged with complementary pinions 55. The two pinions 55 are carried by a suitable shaft 5 5 that is journaled in bearings 57 towards the rear of the machine frame.

Extending downwardly from the carriage St is a trigger 53. On the forward movement of the carriage towards the position shown in Fig. 3, the trigger 58 encounters a stop 59 that is adjustably mounted on a stop rod 58, the encounter with the stop 59 cocking the trigger and opening the grippers 50 to the position indicated in Fig. 3. In the subsequent rearward movement of the reciprocating carriage 5! the trigger 58 clears the stop but encounters a second stop 5! adjustably mounted on the stop rod 6!! and is thereby tripped to cause the grippers 50 to close upon the folded edge of the towel that is presented to the grippers by the afore- On the subsequent forward movement of the carriage 5!, after the towel is drawn forward clear of both the slot 35 and the primary lift plate the grippers 50 are opened automatically to release the towel, and the towel with its first fold completed is dropped upon the secondary support' lfi. At this point in the operation of the machine, the towel has the disposition indicated at 22 in Fig. 15.

The secondary support 45 has the character of a shelf and in the same manner as the receiving platform 30 is divided into two sections separated to form a secondary slot M which is perpendicular to the disposition of the primary slot 35, since the second fold of the towel is to be perpendicular to the first fold.

The secondary folder may comprise a bar 65- unitary with a pair of arms 66 that are fixed radially to a rocker shaft 51, the rocker shaft being journaled in suitable bearings 68 that are attached to the underside of the receiving platform 30. The secondary folder actuated by the rocker shaft 61 oscillates between. an upper position shown in full lines inFig. 7 and a lower position indicated by dotted lines. The downward movement of the secondary folder against a folded towel on the secondary support 45 forces the towel laterally downward through the secondary slot to form a folded edge 23. For the same reasons as heretofore stated, I prefer to employ asecond means to grip the folded edge 23 for the purpose of completing the movement of the towel through the slot, this means being a secondary puller generally designated by numeral '10 best shown in Figs. 6 to 9.

Preferably, a secondary lift plate ll is employed to lift the folded portion 23 of the towel into position for engagement by the secondary puller. This, secondary lift plate is shown mounted on a rocker shaft 12 that is controlled through the medium of a rocker arm 13 (Fig. 2). The swinging edge of the secondary lift plate ll is, by preference, cut away to provide a recess or notch 15 (Fig. 8) to avoid interference with the action of the secondary puller 1B.

The secondary puller HI includes a plurality of grippers 11 on a reciprocating carriage 18. The body of the carriage 18 may be formed, as shown in the drawings, by bottom plate 19 and an upper channcL-shaped plate 80, the two plates forming unitary member having a leftward flange or step 8i and a rightward step or flange 82. The

ends of the carriage 78 are attached respectively to rack bars 83 and are supported by rollers 84 connected inturn to the rack bars. roller 85 at each end of the reciprocating carriage engages a. channehshaped track 85 having a small guide rail 85. The track 85 may be attached to the machine frame in any suitable manner, the drawings showing, by way of example, a bracket 81 interconnecting the track and an angle-iron frame member 88.

The leftward flange or step 8| of the reciprocating carriage 18 may serve as the lower jaw for each of the plurality of grippers i, there being for each of the grippers a lower gripper member 98 of rubber or other suitable material mounted on the leftward flange 8! of the carriage. Each of the grippers ll includes an upper jaw 92 carrying a second resilient gripper member 33 positioned to cooperate with the lower gripper member 96. The upper jaw d2 of each of the grippers may be of sheet metal construction having downwardly extending ears Q i engaging a hinge pin 95, the hingepin being carried by a bracket Q5 mountedon the rightward flange 82 of the reciprocating carriage. Each of' the upper jaws 92 is continuously urged towards closed position by a suitable helical spring ill acting between the body of the carriage iii and one of a pair of ears 98011 the jaw.

Within the carriage l3 and extending lengthwise thereof, a gripper-control shaft iiiil is rotatably confined by the 'two plates of the carriage, a series of screws I0! interconnecting the plates and an angle member W2 within the carriage spaced from the screws 'iill. Extending radially from the shaft mil beneath each of the upper gripper jaws 92 is a short arm it? that carries a terminal roller HM, there being a slot I95 in the upper plate 88 of the carriage to permit the arm N33 to swing upwardly against the jaw member 92. At one end of the carriage, as best shown in Figs. 7, 8, and 9, is a trigger H38 in the form of a pin extending radially from the gripper-control shaft loll through a suitable slot H39 in the upper carriage plate. Toward the end of the leftward movement of the recip rocating carriage 18, the trigger I83 encounters a stop H0 which causes the trigger through the medium of the gripper-control shaft iiiil to swing each of the arms Hi3 towards the right, thereby permitting the grippers 11 to close on the folded edge portion 23 of the towel. Rightward movement of the carriagelfl draws the towel completely through the secondary slot as. Towards the end of the rightward movement of the carriage, the trigger I08 encounters a second stop H4 and is moved leftward to rotate the grippercontrol shaft mil counter-clockwise, the counterclockwise movement of the shaft causing each of the arms N33 to swing upward to lift the upper jaws 92, the gripper then being in cocl :e.d disposition, as indicated by dotted lines in Fig. 7. The stop H4 may be simply an angular member secured to the machine frame by suitable screws H5.

For actuation of the reciprocating carriage I8, the two rack bars 83 associated therewith engage respectively two gears H5 that are keyed to a shaft Ill. The shaft HT is journaled in suitable bearings II8 and carries a driving pinion I20.

The completely folded towels as they are successively released by the secondary puller Iii form a stack I22 on a stacking platform I23. Since I find it desirable to have the top of the stack I22 at substantially a constant level as each successive folded towel is received thereon, I arrange for the stacking platform I23 to be movable vertically. In the construction sug-- gested by the drawings, the stacking platform I23 is supported by four vertical arms I2 1, the two leftward arms I20; being connected to a cross bar I25 and the two rightward arms I24 being connected to a second cross bar I26 to the right. The ends of the left cross bar I25 are connected in turn by bolts I21 to corresponding continuous sprocket chains I28, there being one sprocket chain towards the front of the machine and one towards the rear, as indicated diagrammatically in Fig. 18. The two continuous sprocket chains I28 are in vertical disposition extending between corresponding upper sprockets I35 and lower sprockets Itl, the two lower sprockets I3I being keyed to a common shaft I32. In similar manner the cross bar I25 is connected by bolts I33 at each of its ends to a pair of vertically disposed continuous sprocket chains I34. The sprocket chains I34 extend between upper sprockets I35 and lower sprockets I56, the lower sprockets being keyed to a common shaft Iil'I. A horizontally disposed continuous sprocket chain I39 interconnects a sprocket IIIIl keyed to the shaft I32 and a sprocket MI keyed to the shaft I31, thereby interlocking the four vertically disposed sprocket chains so that the four arms I2 3 supporting the stacking platform IZII rise and fall together to maintain the platform in substantially horizontal disposition at all times.

To counterbalance the stacking platform It'd, I mount a counterweight I46 adjustably on a pivoted counterweight arm I45 and connect either the counterweight or the counterweight arm with the described mechanism for supporting the stacking platform. For example, a sprocket chain I45 may extend from the counterweight IM over an upper sprocket I41 that is coaxial with one of the upper sprockets I30, the sprocket chain I45 continuing downward to connection by a bolt I48 (Fig. 3) with the leftward cross bar I25. A feature of this arrangement is that the greater the number of towels supported by the stacking platform as the stacking platform moves downwardly, the greater the counterbalancing force exerted through the sprocket chain I 18.

For reasons that will become apparent, I prefer to overbalance the weight of the loaded stacking platform to provide a tendency for the platform at all times to move toward its uppermost position against a limiting stop, and to provide a suitable detent mechanism that will normally prevent such upward movement of the stacking platform but will freely permit downward movement. Such a detent mechanism may comprise, for example, a ratchet wheel I69 keyed to the shaft I31 and normally engaged by a pawl I50 that is pivotally mounted on a suitable bracket I5I. The pawl is normally pulled downwardly into engagement with the ratchet wheel by a suitable spring I52, but is provided with a pedal portion I53 by means of which the pawl may be lifted to permit the stacking platform to be moved upward by the counterweight. The stop for limiting the upward movement of the stacking platform may comprise a finger I54 in the path of the counterweight I I I.

A feature of my invention is the conception of the combination with such a movably mounted stacking platform of means movable downwardly against the top of the stack to depress the stacking platform after each folded towel is deposited on the stack, whereby the top of the stack is at substantially the same level to receive each successive towel. A stack depresser for this purpose may include a depresser plate I55 carried by a pair of upstanding arms I56 that are pivotally mounted at their lower ends on a pair of corresponding rocker arms I5'I. Normally a suitable spring means I58 connected with one or each of the arms I56 tends to swing the arms and thereby the depresser plate I55 to the left (Fig. 6), the action of the spring being limited by suitable stop means such as a stop roller I59 positioned to move against a corresponding vertically disposed stop plate I60 mounted on the machine frame. Roller means is employed for the stop to minimize friction when the depresser plate is moved vertically by rotation of a rocker shaft I62 on which the rocker arms I5! are mounted.

When the carriage 78 of the secondary puller Ill nears the end of its rightward movement, it moves against the upper ends of the arms I56 to swing the depresser plate to the right and out of the way until the currently completed towel is dropped onto the stack I22. The subsequent return movement of the carriage I3 permits the stack-depresser assembly to return to normal disposition under the force of the spring means I58, the depresser plate I55 then being above the stack of towels. Before the next towel is deposited on the stack, the rocker shaft I62 is oscillated to depress the stack to the desired receiving level.

Since the towel in process is only partially supported as the secondary puller nears the end of its rightward movement, the towel may tend to drag across the stack I22 and to disarrange the uppermost towel thereon. In the preferred form of my invention, therefore, I provide a reciprocating tray to support the towel in cooperation with the secondary puller.

A suggested action for such a reciprocating tray with relation to the secondary puller and the stack of finished towels may be understood by referring to Fig. 16 that shows diagrammatically the cycle of operation. At stage A of the cycle, when the secondary puller III is at its extreme leftward position and has just gripped the folded edge of a towel T, the tray I55 is at its extreme leftward position. The tray I65 moves to the right simultaneously with the secondary puller I0 until the position is reached that is indicated by stage B, portions of the towel T coming to rest on the tray during this period. Between stage B and stage C of Fig. 16, the tray is stationary, while the secondary puller continuing to move to the right drags the towel T across the tray. Between stages C and D, the tray pauses but tilts downwardly towards the stack I22 as the secondary puller 19 reaches its extreme rightward position and drops the leading end of the towel 'I' on the stack. The stage E shows the puller at its extreme rightward position with a rightward portion of the towel T resting on the stack I22 and a leftward or trailing portion of the towel resting on the inclined tray I65. In the initial movement of the puller in the reverse direction to the left, the tray rotates to its normal substantially horizontal disposition, the relative position of the elements then being as indicated at stage F. Between stage F and stage G, the tray moves to the left simultaneously with the leftward movement of the secondary puller 10, and between stage G and stage A at the beginning of the next cycle, the tray remains stationary while the puller continues its leftward movement. It is apparent that such a tray may have its own separate actuating mechanism timed to operate in the sequence indicated, but I prefer to operatively interconnect the tray and the secondary puller in a manner to provide the required action, as will now be described. I

The tray IE5 is supported towards its left end, as indicated in Figs. 3 and 6, by a cross bar Hit, the cross bar being supported in turn by rollers I61 mounted on each of its ends. The rollers I61 engage corresponding channel-shaped tracks I68 that are in substantially horizontal disposition below the level of the rack bars 83 that control the secondary puller 10. A stop I10 in the formv of a block mounted in oneor each of the tracks IE8 -is in the path of the roller or rollers I51 to limit the movement of the tray to the right, as best shown in Fig. 6, and a second stop means III of similar construction may be provided to limit the leftward movement of the rack, as indicated by Fig. 6a,v I

Each of the longitudinal edges of the tray IE5 is provided with a pair of spaced guide rails I12 between which and in sliding engagement therewith is mounted a suitable slide block I13. As best shown in Figs. 12 and 13, each of the two slide blocks is provided with friction shoes I14 mounted in suitable bores I15 and continuously urged against one of the rails I12 by confined spring means I16. A pair of links I19, one link lying to each side of each slide block I13, is pivotally connected by a pin I to the corresponding rack bar 83 and by a pin I8I to the slide block I13. By this arrangement the links I19 cooperate with the guide rails I12 to confine the slide block I13. A suitable helical spring I 83 is connected to either each of the pairs of links I19 or to each slide block I13. For example, each spring I83 may be connected to a slide block I13, as shown in the drawings, the other end of. the

spring being connected to the carriage 18 of the secondary puller. The action of the springs I33 is limited by pins I84 on the rack that serve as stops for swinging movement of the links I19, the tray 55 being substantially horizontal when the links are drawn against the pins I84, as indicated in Fig. 6. g

The arrangement described functions in the following manner to provide the sequence of tray movement depicted in Fig. 16. At stage A in the sequence, the secondary puller is at its extreme leftward position, the rollers I81 of the tray are against the left stop means HI, and the slide block I13 is at the extreme left end of the two guide rails I12. As the secondary puller initially moves rightward to the disposition of stage 33, the frictional engagement of the slide block I13 with the corresponding guide rails is sufiicient to cause the tray to follow the movement of the secondary puller as the slide blocks are drawn rightward through the medium of the springs I83. At stage B the stops I'm are encountered by the tray rollers I61 to prevent further rightward movement of the tray. The rack bars 83 that drive the secondary puller continue to move rightwardly, however, and with the tray stationary the slide blocks I13 slide along the guide rails I12 until at stage C the slide blocks encounter stops I85 (Fig. 12) at the rightward ends of the guide rails I12. Subsequent rightward movement of the secondary puller rack bars 83 causes the links H8 to be rotated in a manner to tilt the rightward end of the tray downward in opposition to the force of the springs I83, the

position of the tray at stage D being indicated in dotted lines in Fig. 8. At the end of the rightward movement of the secondary puller, stage E3 of 16, the leading end of the folded towel has been dropped upon the stack I22. and the trailing end rests upon the inclined tray I55.

During the initial part of the reverse or leftward movement of the secondary puller rack bars 83, the links I19 are rotated upward to permit the springs I83 to return the tray to its normal horizontal disposition.v The towel readily slides off the tray, in the first place,.because only a portion of the towel is on the tray, and, in the second place, because the tray is relatively smooth, whereas the towel tends to cling to the towel of the stack on which it rests. 'At stage F the tray begins to move leftward becauseof frictional'engagement with the guide rails I12 by the slide blocks I13, but at stage G the tray rollers I51 encounter the rearward stop means I1I to hold the tray stationary. Continued movement leftward by the secondary puller causes the slide blocks- I13 to move to the left end of the slide rails I12, thus bringing the tray and secondary puller back to stage A for a repetition of the cycle.

It is to be noted that the depressor plate I55, acting on the stack of towels in the course of each of the above cycles of tray operation, serves to maintain the top of the stack at substantially the same level as each of the successive towels is deposited thereon. The cooperation. of the various members results in a neat and uniform stack of finished towels. When the stacking platform I23 approaches its lowermost limit of movement, if not before, the stack of towelsis removed and the pedal I 53 is depressed to permit the stacking platform. to move upwardly to a suitable position to receive the initial towel for a new stack.

Those skilled in the art will readily appreciate that various forms of interlocking actuating mechanisms may be employed to operate the moving parts. described above in a sequence to practice my method of folding. In the preferred form of my invention the folding operation, as a whole, is divided into two stages that are carried out concurrently in one machine cycle, there being normally two successive towels in process in the machine simultaneously. Attention is directed to Fig. 17 showing graphically the sequence of machine movement in terms of rotation of the main shaft I95, broken lines rep resenting movements that are ineffective in the actual folding procedure and full lines representing movements acting upon a towel in furthering the folding procedure. A mechanism suggested as suitable for actuating the various machine partswill now be described in the light of this graph.

As best shown in Figs. 2 and 3, a motor I supported by frame members I9I operates through a speed reduction device I92, a' driving pinion I53 that meshes with a driven pinion I94. The pinion I94 is mounted on a drive shaft I95 for rotation independently thereof and is provided with a clutch sleeve I96 having clutch teeth I91. Keyed to the drive shaft I95 is a slidable clutch sleeve 22!] having teeth 2i adapted to mesh with the teeth of the first-mentioned clutch sleeve I96, the clutch sleeve 206 being continuously urged towards such engagement by a suitable spring 252 embracing the drive shaft I95 between the clutch sleeve 202 and a collar 293. The clutch sleeve 255 has a reduced peripheral portion 294 and an enlarged peripheral portion 225, the edge of the enlarged peripheral portion forming an inclined cam shoulder 226 that terminates in a stop shoulder Directly above the clutch sleeve 250 is a bracket 208 secured to a frame member 209 by suitable bolts 2H], the bracket having vertically spaced arms 2II, 2I2, and 2I3. Slidingly mounted in the two lower arms 2 and 2E2 of the bracket is a clutch pin 2| having a stopcollar ZIB normally abutting the arm 2II, the clutch pin being urged continuously downwardly by a helical spring ZITembracing the pin between the stop collar and the arm 2I2. The clutch pin 2I5 normally engages both the cam shoulder 2G5 and the stop shoulder 28] of the clutch sleeve 28d, thereby holding the clutch sleeve stationary, 'out of engagement with the clutch sleeve I96, as shown in Figs. i and 5.

Slidingly mounted in suitable apertures in the upper two arms 2I2 and 2I3 of the bracket 208 is a release plunger 220 that is continuously urged downwardly by a spring 22I embracing the plunger between the upper arm 213 and a stop collar 222 on the plunger, the stop collar normally resting against the arm 2I2. Pivoted to the lower end of the release plunger 220 is a trip arm 223 that extends through a guide slot 224 in the bracket arm 2| I. The trip arm223 has a shoulder or tooth 225 adapted to engage the stop collar 2I6 to raise the clutch pin 2I5. The trip arm 223 normallyis held against the reduced peripheral portion 204 of the clutch sleeve 256 by the action of aspring 226 that interconnects the lower end of the trip arm and the frame member 229, the tooth 225 at this position of the trip arm being under and in engagement with the stop collar 2I6 of the clutch pin.

The release plunger 22B is operatively connected by a link 228 with a rocker arm indicated by dotted lines at 229 in Fig. 2, the arm being mounted on the end of a rocker shaft 232. The rocker shaft 23!! is actuated by a rocker arm 23! that in turn is actuated through a link 2232 from a rocker arm 233 near the bottom of the machine. The rocker arm 232 is mounted on a rocker shaft 234 that is controlled by a clutch pedal 235. In the inactive position of the clutch control mechanism the clutch pedal 235 is held in elevated disposition by the action of the spring 226 associated with the release plunger 220, the normal disposition of the clutch mechanism being shown in full lines in Fig. 4 and in Fig. 5.

Whenever the clutch pedal 235 is depressed to elevate the release plunger 225, the tooth 225 of the trip arm 223 lifts the clutch pin 2 I5 to release the clutch sleeve 220 whereupon the spring 222 forces the clutch sleeve 225 into operative engagement with the clutch sleeve I26. The drive shaft I95 being operatively connected with the motor I90 rotates in a clockwise direction, as viewed in Figs. 3 and 4, and the resultant rotation of the clutch sleeve 20E) brings the enlarged peripheral portion 265 of the clutch sleeve against the trip arm 223 to move that arm to the left sufiiciently, as indicated in dotted lines in Fig. 4, to displace the tooth 225 from the clutch pin collar ZIB, whereupon the clutch pin is released to drop towards its normal. disposition in the path of the stop shoulder 22? of the clutch sleeve 2913. Because of this clutch arrangement, the clutch will remain in driving engagement only for a sufiicient period to cause the drive shaft I95 to make a single rotation, it being necessary to release the clutch pedal 235 and to subsequently depress the clutch pedal to cause the drive shaft to make a second rotation. One rotation of the drive shaft I95 is indicated in degrees in Fig. 17, the 360 representing one complete machine cycle.

I contemplate having the primary folder swing downwardly in the course of a machine cycle suficiently to pass the blade 38 into the primary slot 35 and then to return to the raised position at the end of the machine cycle. For example, the movement of the primary folder may be such as indicated by the line 231 in Fig. 17, the solid portion 238 of the line indicating the time interval during which the blade 38 is forcing the towel laterally downward through the primary slot 35. In the upward movement of the primary folder there is preferably a short pause as indicated by the horizontal portion 239 of the line, the purpose of this pause relating to the primary lift plate, as Will be apparent below.

To provide movement of the character indicated by the line 231 in Fig. 1'7, I mount a cam 249 on the'olrive shaft I95, the cam being in the form of a plate cut to the required configuration. The periphery of the cam 230 is engaged from below by a follower in the form of a roller 24! journaled betweentwo parallel bars that constitute an arm 242. The arm 242 is pivoted on a fixed shaft 243 and the swinging end of the arm is connected by a link 2 34 with a rocker arm 245 that operates the previously mentioned rocker shaft ii!) for the primary folder. A helical spring 24'! connected at one end to the frame of the machine and at the opposite end to a rocker arm 24B extending from the rocker shaft 42 serves to urge the rocker shaft continuously in a direction to rotate the rectangular frame 39 of the primary folder towards the rearward and upward position thereof. It is apparent that the effect of the'spring 241 is to force the roller 24I continuously against the underside of the cam 240.

Since it is possible for an operators hand to be caught under the primary folder blade 38 as the blade moves into the primary slot 35, I prefer to arrange for the primary folder to be operated in a yielding manner whereby the movement of the primary folder may be stopped by the operators hand without exerting injurious force. The desired effect may be obtained, for example, by making the link 2 yieldingly extensile. Thus, I propose to have the link comprise two sections telescoped for sliding action, as best shown in Figs. 10 and 11. The upper section of the link 244 comprises a pair of spaced bars interconnected by spaced pairs of small plates 25I, the bars and plates slidingly embracing an intermediate bar 252 that constitutes the lower section of the link. The two sections of the link may be yieldingly interconnected by a pair of helical springs 253 that are connected at their upper ends to a cross pin 254 in the spaced bars 250 and are connected at their lower ends to a cross pin 255 in the bar 252. Normally, the springs 253 hold the extensile link 244 in contracted disposition, the contraction of the link being limited by a suitable stop plate 2'56 that is held by a nut 25'! on the lower pin 255., the stop plate abutting the lower end of one of the spaced bars 258. If there is any abnormal resistance to the downward movement of the primary folder, the link 244 will yield longitudinally, the range of extension of the link being at least sufficient to permit the primary folder blade 38 to stop just above the primary slot.

While the primary lift plate 46 may be actuated directly from the drive shaft I95, I find it convenient to connect it with the rocker shaft 40 of the primary folder mechanism for actuation. A cam 260 (Fig. 3) mounted on the rocker shaft 40 has two outer dwells 26! and 252 separated by an intervening valley. Cooperative with the cam 250 is a yoke 263 that includes two rectangular frames 264 carrying a cam follower in the form of a roller 265. The two rectangular frames 24!) lie on opposite sides of the cam 26!! and slidingly engage the rocker shaft 4!]. A rod 266 extending from the yoke 263 and unitary therewith is connected with a rocker arm 26'! that controls the previously mentioned rocker shaft 47 on which the primary lift plate is mounted. A spring 268 interconnecting the yoke 263 and the frame of the machine continuously urges the yoke upward and to the right, as viewed in Fig. 3, the action of the spring tending to swing the primary lift plate 46 upwardly and also tending to hold the roller 265 against the cam 260.

The proposed movement of the primary lift plate 46. as determined by the above described mechanism, is indicated by the line 210 in Fig. 17. At the beginning of the machine cycle. the roller 260 is riding against the outer dwell 25! of the earn 2%. thereby holding the primary lift plate at its lower position in opposition to the spring 268, all of which may be understood by referring to Fig. Rotation of the cam 26% in clockwise direction permits the roller 265 to traverse the va ley between the two walls of the cam, thereby causing the primary lift plate to move up and down, as indicated by the peak 2.12 in the line 210. This particular oscillation of the lift plate is of no service in the folding operation; the important fact is that the lift plate pauses at its lower position for an interval in" dicated by the horizontal portion 213 of the line 210, this interval occurring while the primary folder 44 completes its downward movement and then retreats upwardly. The folded edge por-- tion 2| of the towel (Fig. 15) formed by the downward movement of the primary folder now comes to rest on the primary lift plate MS. as indicated by the beginning of the solid portion 214 of the line 210, the roller 255 at this juncture being against the second outer dwell 265. of the cam 26!).

The rearward movement of the primary folder 44 and the concurrent reverse movement of the cam 269 permit the roller 255 to enter the valley between. the two outer dwells 261 and 262 of the cam, at which point the roller 285 pauses because the primary folder pauses at this time as previously mentioned with reference to the horizontal portion 239 of line 231. It is apparent then. that after the primary folder begins its upward movement, the primary lift plate automatically lifts or deflects upwardly the folded edge portion 2| of the towel, and then pauses with the towel held in'a disposition to be fed to the primary puller 44. The subsequent rotation of the cam 260 as the primary folder resumes its rearward movement forces the roller 265 outwardly onto the outer dwell 26! of the cam thereby depressing the lift plate for the remainder of the machine cycle.

During the first half of the machine cycle, the primary puller l l moves to the leftward, until at the end of such movement the trigger 5B is tripped to cause the grippers 50 on the carriage 5| to close into engagement with the folded edge portion 2! of the towel, the towel being supported at this juncture on the elevated lift plate 46. The rearward movement of the primary puller carries the towel forwardly to clear the primary slot as indicated by the solid portion 21'! of the line 218, the towel being dropped from the grippers when the trigger 58 strikes its forward stop.

To actuate the primary puller 44 in a manner corresponding to the line 218 of the graph, I

provide a cam 280 on the drive shaft I 95, the cam being in the form of a plate cut to the required configuration, as best shown in Fig. 14. Cooperative with the cam 285 is a yoke generally designated 28l that incorporates a pair of guide arms 282 on each side of the cam, each pair of guide arms slidingly engaging the drive shaft I95 or a suitable sleeve on the drive shaft. Journaled in the yoke 28l is a cam follower in the form of a roller 284 that rides upon the peripheral edge of the cam 28%). downwardly against the cam at all positions of the cam, a pair of springs 285 are connected to corresponding arms 2% integral with the yoke, the lower ends of the springs being connected to a corresponding pair of arms 28'! that are pivoted to the fixed shaft 243. The lower arms 28'! carry a roller 289 therebetween that at all times engages the periphery of the cam 280 from below. It will be apparent that the spring 285, in effect,

operates in tension between the upper roller 284 A and the lower roller 289 to cause the upper roller to follow the cam at all times.

Extending upwardly from the'yoke 28! as a unitary part thereof is a rack arm 29!) that meshes with a pinion 292 (Fig. 3) keyed to the previously mentioned shaft 56 that controls the action of the primary puller 4d. The rack arm 29!] is held against the pinion 232 in engagement therewith by an adjacent guide roller 254 having a grooved periphery that engages the rack arm. apparent that the combined yoke and re ck arm will reciprocate in a rectilinear path by virtue of the fact that the lower end of the combination is guided by the drive shaft I95 and the upper end of the combination is guided by the pinion 292 cooperating with the guide roller 294.

The action of the secondary folder as indicated by the line 295 of the graph may be such that near the end of the machine cycle the secondary folder moves downwardly after the towel is released by the primary puller and forces the towel through the secondary slot, the secondary folder acting on the towel during the period represented by the solid portion 295 of the line 21 5.

For actuation of the secondary folder in the manner suggested, I provide a cam 298 on the drive shaft I to cooperate with a rocking lever 300. The rocking lever shown in the drawings constitutes a pair of parallel bars fulcrumed on the previously mentioned shaft 243, the rear end To force the follower 2B4 It will be of the lever carrying a roller 3M in constant contact with the cam 298 and the forward end of the lever being pivotally connected to a link 332. The upper end of the link 332 (Fig. 2) is connected to an arm of a bell crank 333 that is pivoted on a spindle 304. The particular bell crank shown is simply a triangular plate. The second arm of the bell crank 303 is connected by a link 305 with a rocker arm 3% carried by the previously mentioned rocker shaft 6? that controls the secondary folder. A suitable spring 331 interconnecting the frame of the machine and the bell crank 303 pulls downwardly on the bell crank to hold the roller 33! against the cam 298, the spring thereby tending to swing the secondary folder upwardly as permitted by the cam. The cam is shaped to cause the secondary puller to rise at the initiation of the machine cycle and to remain elevated until after the primary puller releases the towel to the secondary support 45.

Since the secondary lift plate H is adjacent the secondary folder 65, I find it convenient to operatively associate the lift plate with the above described mechanism that actuates the secondary folder. To this end I connect a spring 339 with the previously mentioned rocker arm 13 that controls the lift plate rocker shaft 12, the spring having one end anchored to the machine frame and being disposed to cause the lift plate 'H to swing upwardly. The uppermost position of the lift plate may be adjustably fixed by a set screw 3H) in a plate 3H on the machine frame, the set screw being positioned to block the counterclockwise rotation of the rocker arm 13 as viewed in Fig. 2. The link 3% of the secondary folder mechanism carries a downwardly projecting camshoe 2I3 that is carried into and out of engagement with a cam pin 3H3 on the rocker arm 13, thereby depressing and releasing the rocker arm to depress and raise the secondary lift plate I I.

The shape and disposition of the cam shoe 3l2 are such as to actuate the secondary lift plate in the manner represented by the line 3 l5 in the graph. At the beginning of the machine cycle the secondary lift plate is depressed by engagement of the cam shoe 3l2 with the pin 343, the cam shoe at this time being in the act of moving leftward as the secondary folder is being swung upward. The folded edge portion 23 of the towel rests upon the stationary secondary lift plate as indicated in the graph by the fact that the line 3H3 has an initial solid portion in horizontal disposition. As the pin 3H3 escapes from the cam shoe (2 in the latter part of the upward movement of the secondary folder, the secondary lift plate is forced upwardly by the spring 333, thereby lifting up the folded edge of the towel for feeding to the secondary puller Ill.

The desired action of the secondary puller i is indicated by the line 3 iii of the graph. During the initial portion of the machine cycle. the secondary puller is moveing leftward and the trigger I38 is tripped as the limit of leftward movement is reached, whereupon the secondary puller grips the towel and draws it to the right to clear the secondary slot. The graph shows the line 3l6 as solid along the portion between the two points at which the trigger N33 is acted upon by the stops i it! and l M. Before the end of the machine cycle, the return movement of the secondary puller is initiated.

Such actuation of the secondary puller l0 may be achieved by providing a cam 3|! (Figs. 3 and 14) on the drive shaft I95 to cooperate with associated mechanism in the same manner as the cam 230 that controls the primary puller. A yoke 3&8 (Fig. 2) carrying a roller 3l9 acting against the cam 3!! from above has a pair of arms 32b extending downwardly on each side of the cam in sliding engagement with the drive shaft I35 or a suitable sleeve thereon. The yoke 3H3 is continuously urged downwardly by a pair of springs 32! that have their upper ends connected with the yoke and their lower ends secured to corresponding parallel bars 323 that constitute an arm 324 pivoted to the previously mentioned shaft 243. The arm 324 carries a roller (not shown) positioned under the cam 3", corresponding in function to the previously mentioned lower roller 289 associated with cam 28!), so that the springs hold the roller 3) down against the cam.

The yoke 3H3 has a rack bar 32'? unitary therewith extending upwardly into mesh with the previously mentioned pinion I20 (Fig. 6) that drives the secondary puller. A guide roller 32% holding the rack bar in mesh with the pinion I23 cooperates with the pinion to guide the upper end of the combined yoke and rack bar.

Since the tray IE is operated by movement of he secondary puller ill, as heretofore described, the sequence of tray movements will fall in the order indicated by notations along the line 329 of Fig. 17.

The mechanism for actuating the stack-depressing mechanism previously described may start with a cam 33B (Figs. 2 and 3) on the drive shaft I95. An. arm 332 that actuates a rocker shaft 333 carries at an intermediate point thereon a roller 334 that follows the periphery of the cam 333, the roller being pressed continuously against the cam by a suitable spring 335 connecting the swinging end of the arm 332 and the machine frame. The rocker shaft 333 carries a second rocker arm 336 that is connected by a link 33? with a rocker arm 338. The rocker arm 338 is on the previously mentioned rocker shaft 532 that controls the vertical movements of the stack-depresser assembly. The various movements of the depresser plate I55 relative to the machine cycle are represented by the line 340 in Fig. 17.

It will be apparent to those skilled in the art that the basis of the described machine is a fundamental conception of a new method of folding towels and the like that is independent of any particular machine and may be performed by various mechanisms. While the-method as practiced herein involves forcing a sheet through a slot, in other practices such forcing may be dispensed with, especially when the path of towels in process need not be confined to the compact space of the machine herein described. As an example of how my method may be practiced without employing the edges of a slot to cooperate in the folding process, Fig. 19 shows schematically how a towel may be folded simply by lifting it from a horizontal plane by a member extending along the desired line of fold of the towel, the towel being lifted until the portions on opposite sides of the fold line are juxtaposed.

At the beginning of the folding process shown in Fig. 19, the unfolded towel 345 rests upon two substantially horizontal support members 345 spaced to define a slot 341. Initially, a pair of arms 348 and 343 that carry respectively folding bars 350 and 35! are disposed below the support members 333. The arms 348 and 349 are carried in turn by stub shafts 353 and 354 respectively that are slidingly keyed in a hollow drive shaft 2,204,268 355'. Both the'arms have the same angular relation to the drive "shaft 355 so that the folding bars 350 and 35! are always in alignment with each other. At the beginning of the folding process, the ends of the two folding bars 356' and 351 are close together so that two bars, in effect, constitute a single bar.

Clockwise rotation of thedrive shaft 355 rov tates the arms 348 and 349 to carry the folding bars 350 and 35! upwardly through the slot 341. The two folding bars 356 and 35! move against the under side of the towel 345 along the desired fold line of the towel and carry the towel upwardly until the portions lying to either side of the fold line are draped'against each other, the disposition of the towel at this juncture being shown at 356. Continued rotation of the arms 348 and 349 leads the folded towel onto an elevated second pair of support members 358 and 359 that define a second slot 366. At this point in the operation, the drive shaft 355 pauses in its rotation momentarily while the two stub shafts 353 and 354 slide away from each other axially until the two folding bars 355 and 35I are entirely withdrawn from the towel, leaving the towel in the disposition shown at 361. The two arms 343 and 349 are then rotated back to the starting position.

The second fold is accomplished in substantially the same manner as the first fold by a pair of arms 363 and 364 that carryrespectively a pair of cooperating folding bars 365 and 366. The two arms 363 and 364 are carried in the same manner as heretofore described by a pair of axially slid- I ing the completely folded towel on the platform,

as indicated at 313. y

The constructions set forth herein for the purpose of disclosure and to illustrate the principles of my invention will suggest to those skilled in the art various changes, modifications, and other embodiments that do not depart from the essence of my inventive concept. I reserve the right to all such changes, modifications, and embodiments that properly come within the scope of my appended claims.

I claim as my inventioni 1. In a machine of the character described, means for making a fold in a flexible sheet, said means comprising: means to support said sheet at a first level; means forming a slot under the supported sheet; reciprocating means movable dovmwardly against said sheet along the desired line of fold to force said sheet partially through said slot to form a leading folded edge in the sheet below said slot; means to lift said folded edge to a feed position; means movable along a second lower level to engage said folded edge at said feed position and to complete the movement at a flrst'level; means'to support said sheet subsequently at a' second level; means forming a slot under the sheet when the sheet is on saidfirst support; means to force said sheet laterally downwardly partially through said slot to form a leading folded'edge in the sheet; gripper means movable towards and away from said slot in a path between said two support'means, said gripper means being adapted to approach said leading folded edge of the sheet in an open position, to close upon said folded edge, topull said folded edge until the sheet clears said slot, and to open thereafter to release said sheet to said second support; and means to actuate said forcing means and gripper means in timed sequence.

3. A folding machine of the character described for folding a sheet of flexible material, said machine having: a first support means providing a slot; a second lower support means providing a second slot; means operable when said sheet is on said first support to force said sheet downwardly along a desired fold line through said first slot sufficiently to form a leading folded edge in the sheet; gripper means movable towards and away from said first slot in a path between said two support means, said gripper means being adapted to approach said leading folded edge of the sheet in open position, to close until the sheet clears said slot, and to open thereafter to release said sheet to said second support; means operable when said sheet is on said second support to force said sheet downwardly along a desired second fold line through said second slot to form a second leading folded edge in the sheet; and a second gripper means movable towards and away from said second slot in a path below said second support, said second gripper means being adapted to approach said leading folded edge of the sheet in open position, to close upon said folded edge, to pull said folded edge until the sheet clears said slot, and to open thereafter to release said sheet.

4. A machine of the character described for folding a flexible sheet, said machine having in combination: means forming a slot to receive the sheet; means to force said sheet laterally along a desired foldline of the sheet through said slot and to release the folded sheet to a receiver for folded sheets; and a reciprocating tray to receive" the trailing end of the folded sheet as the sheet.

leaves said slot.

5. A machine as set forth in claim 4 in which said tray moves in the same direction as the sheet prior to the release of the sheet and moves in to form a leading folded edge; gripper means to seize said folded edge, to pull said sheet completely through said slot and then to release the folded sheet; and a reciprocating tray to support a portion of said sheet as said gripper means moves away from said slot.

7. A machine of the character described for folding a flexible sheet, said machine having in combination: means forming a slot to receive the sheet; means to force said sheet along a desired fold line of the sheet through said slot sufficiently to form a leading folded edge; gripper means reciprocating towards and away from said slot, said gripper means being adapted to seize said folded edge, to pull said sheet completely through said slot and then to release the folded sheet; and a reciprocating tray to support a portion of said sheet as said gripper means moves away from said slot, said tray, moving with said gripper means as the gripper means initially moves away from said slot, then pausing until after the gripper means initiates its return movement, and finally returning with the later part of the return movement of the gripper means.

8. A machine substantially, as set forth in claim '7 in which said tray tilts downwardly during its pause period.

9. In a machine of the character described, means for making a fold in a flexible sheet, said means comprising: a first support for said sheet at a first sheet-position, said support having a slot disposed to extend under the sheet from one edge of the sheet to the opposite edge of the sheet; a second support for supporting said sheet subsequently at a second position; means to force said sheet laterally downwardly partially through said slot in said first support to form a leading folded edge in the sheet; gripper means movable towards and away from said slot in a path extending under said first support, said gripper. 

